Electric metering system.



No. 67|,272. Patented Apr. 2, 190i.

, W. C. FISH.

ELECTRIC METERING SYSTEM.

' (Application fil'ed Jan. 18, 1899.

(No Model.)

RH T l \A/I NEEEEE.

A. HM.

m: "cams Pzizns co. Moro-urns Nrrnn STAT S ATENT FFICE.

WALTER G. FISH, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

ELECTRIC METSERING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 671,272, dated April 2, 1901.

Application filed January 18, 1899. Serial No. 702,506. (No model.)

To all whom it may concern:

Be it known that I, WALTER O. FISH, acitizen of the United States, residing at Lynn, in the county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Electric Metering Systems, (Case No. 909,) of which the following is a specification.

Until very recently it has been the custom to charge consumers of electrical current or energy supplied from central stations a certain specified price, depending upon the amount of current or energy used by each particular consumer. Each consumer has been supplied usually with a recording wattmeter acting to integrate the product of current by electromotive force from instant to instant, and the charges were proportional to the readings of this instrument. Later,however, it began to be realized that this system of charging was unfair both to the consumer and to the station. The cost of supplying electrical energy to a particular consumer depends not only on the amount of energy which he actually does take during a given month, but also on the maximum demand which he makes upon the station. To speak more accurately, the cost of supplying energy from a station is the sum of two quantities-first, the cost of being ready to supply acertain maximum load, and, second, the cost of actually supplying a certain definite load for a certain definite time. The first item contains such matters as, for example, the interest on the cost of the generators, engines, &c., and the salaries of the general officers, engineers, superintendents, &c., while the second item takes account of the increased amount of coal, oil, &c., used when a large load is carried for a definite time. It has therefore been proposed to place in circuit with each wattmeter a maximum recording meter, which shall indicate the maximum demand made by the consumer upon the station during a specified time and to charge the consumer a certain amount for the maximum demand which he makes and a certain addiand satisfactory in all cases where the maximum demand is sure to occur during the heavy-load hours; but evidently it is possible that a certain consumer may take his maximum load for a given month during the daytime, and it is unfair that in such a case he should be charged heavily, since during the day the station is usually capable of supplying a load far in excess of that which it actually carries, and, in fact, is usually glad to sell current at a reduced rate. Anothersolution of the difficulty has been to install meters which were adjusted to read at one rate during the full-load hours and at another rate during the low-load hours. This is satisfactory in certain special cases, but is sometimes objectionable, since it fails to take account of the fact that a consumer may use lights for only a very few hours each month, and thus pay only a very small hill, though his load when it does come is such as to cause great difliculty and annoyance to the station. An example of such a consumer would be a theater in a country town, which might be open only once a week, but which, nevertheless, would take a heavy load When the station was least able to furnish it, without running up a bill in any way large enough to compensate for this objection.

My present invention contemplates overcoming the difficulties above mentioned by insertingin the consumers circuitsmaxim ummeters which are inoperative during the lowload hours. I further contemplate combining two-rate meters with maximum-demand meters. I further contemplate an arrangement by which the same device which actuates the two-rate meter may also serve to cut in and out the maximum-demand meter. The present claims are restricted to an improved system foraccomplishing these ends. The claims for the mode of carrying it out are reserved for a companion application, forming a division hereof, filed January 26, I901, Serial No. 44,777.

The accompanying drawing represents a system of distribution arranged in accordance with one form which my present invention may take.

A is a source of electric currentas, for example, a generator at a central station from which extend lines B G. Branch circuits leading to individual consumption-circuits are shown at D E and D E. Translating devices, such as lamps L L and motors W, are arranged as indicated in the consumption-circuit.

Referring particularly to the first of the stations shown, it will be seen that a recording-wattmeter F of the usual construction is inserted, with its field-coils in series with the mains D and its armature in multiple between the mains D and E. The usual resistance R is placed in series with the armature, and an additional resistance S, capable of be ing cut out by a switch G, is inserted in series with the resistance R. In series with the main D, I also insert a maximum-meter H. This instrument is indicated here only conventionally as consisting of an arm a, carrying a pencil 1), moving over a scale 0. A solenoid d attracts the core 6 and pulls the arm a downward against the action of an adjustable springf. Evidently the pencil b will trace a line, as indicated at g, upon the scale 0, whose length will indicate the maximum load taken by the consumer since the scale was renewed. Any other suitable maximumrecording instrument may be used in place of the one shown. The maximum instrument is shunted by a switch K in such a way that when the switch is closed the instrument will cease to operate.

It is obvious that by suitably manipulating the switches G and K the method above outlined may be carried out. As an. illustration of one manner in which this may be accomplished I have shown an additional wire M extending through the system, with branches N N at the particular consumption-circuits. Each of these branches leads through a solenoid O, which solenoid actuates an insulated rod P against the action of a spring Q. In the central station I arrange a switch T, which is capable of supplying current to the wire M, preferably through a resistance U.

The operation of the system thus described is as follows: During the hours of heavy load for example, from five oclock p. m. until midnight-the switch T is closed. Current thus flows from the main B, through the resistance U, switch T, and wire M, to the wire N, and thence through the solenoid O to the wire E and back to the station. The solenoid thus energized closes the switch G and opens the switch K. The result is to cut out the resistance S in series with the resistance R in the armature-circuit of the recording-meter and to open the shunt around the maxi mum-meter. The two-rate meter now runs on the high rate and the maximum-meter becomes operative. Under such conditions the customer will naturally use as little current as possible and will avoid taking a heavy load even for a short time. As the load goes off from the sta tion the switch T will be thrown to the position shown in the drawings. This will opencircuit the coil 0, and the spring Q will close the switch K and open the switch G. The recording-meter F will nowrun on the low rate and the maximum-meter will be inoperative. This will encourage customers to use current freely at the time when the station is best able to furnish it.

It will be obvious that my invention is not restricted to the particular two-rate'meter apparatus shown, nor to the particular method of control shown, as I may use, for example, any of the arrangements now well known in the art, devised by Kapp, Barstow, and Oxley.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In an electric metering system, the combination of a supply-circuit, registering-meters at the consumers stations, maximum-demand meters at the consumers stations, and means for cutting the maximum-demand meters into the consumerscircuit at determinate hours.

2. The combination with leads from an electric'supply system, of a consumption-circuit and a two-rate meter device and a maximum meter device in series with the consumptioncircuit.

3. The combination with leads from an electric supply system, of a consumption-circuit and a two-rate meter device and a maximum meter device in series with the consumptioncircuit, and means for cutting out the maximum instrument during the period of low rate.

4. The combination with. leads from an electric supply system, of a consumptionrcircuit, a maximum instrument in operative relation with said circuit, and means for cutting out the maximum instrument without affecting the supply of current to the circuit.

5. In a system of electric distribution, one or more consumers circuits supplied with in.- tegrating and maximum instruments, and means operated from a central point for simultaneously varying the rate and cutting out the maximum instrument.

6. The combination of a two-rate meter device and a maximum instrument in operative relation to the same circuit, and means whereby the normal operation of the two-rate device cuts out the maximum instrument during the period of low rate.

In witness whereof I have hereunto set my 

